Will a missing oil cap cause engine damage?

A garage serviced my Honda Civic (2006) recently, but when I got home (30 minute drive) I noticed the oil cap was missing. There was oil covering the inside of the engine and smoke/oil on the floor. I'm going back today to tell them to fix/clean my car, but am worried that driving without the cap on could have caused engine damaged, should I be worried?
Depends how much oil is left in the engine. Dip it, and if it's light top it up. If the cap is missing, it's down to Halfords to bring one out to you, top up the engine, then take it away and clean it up, leaving you with transport in the meantime. Easy mistake for them to make, but there's no excuse. If they mess you about, tell them you will have an independent garage do it all, then sue them for the bill.
Answered by Honest John on

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